In the most comprehensive account to date of the missing Malaysia Airlines Flight 370’s fate, Malaysian Prime Minister Najib Razak on Saturday said that the plane was steered off course after its communications systems were intentionally disabled and that it could have flown for seven additional hours.

Caption

In the most comprehensive account to date of the missing Malaysia Airlines Flight 370’s fate, Malaysian Prime Minister Najib Razak on Saturday said that the plane was steered off course after its communications systems were intentionally disabled and that it could have flown for seven additional hours.

March 15, 2014Crew members look outside windows from a Malaysian air force CN235 aircraft during a search-and-rescue operation to find the missing Malaysia Airlines Flight 370 over the Strait of Malacca. Prime Minister Najib Razak said on Saturday that Malaysia was ending its search for the vanished jetliner in the South China Sea after investigations indicated the missing plane likely turned far to the west. Mohd Rasfan/AFP/Getty Images

It was a good night for flying, with benign weather all the way to Beijing. Malaysia Airlines Flight MH370, the red-eye from Kuala Lumpur, climbed for 20 minutes and leveled out at 35,000 feet, cruising at 472 knots over open water.

“All right, good night,” the pilot said to air traffic controllers behind him in Malaysia. He was supposed to say hello soon to the controllers ahead of him in Vietnam.

The handoff never happened. Flight MH370, with 239 people aboard, went silent. The transponder — the radar beacon that identifies a plane and its location — stopped transmitting. So did another communication system that sends engine data to computers on land via satellite. To the extent such a thing is possible, the Boeing 777 became a ghost plane, a modern-day Flying Dutchman.

More than a week later, what happened inside that plane around 1:21 a.m. local time on March 8 remains unknown — but investigators now believe it was not an accident.

Satellite information indicates that the plane flew for another seven hours, Malaysian Prime Minister Najib Razak said Saturday, and he said the movements of the plane as tracked by military radar were “consistent with deliberate action by someone on the plane.” He said there is renewed focus on the people onboard, including the cockpit crew.

New data has provided an arc of possible locations for Malaysian Flight MH370.

If the plane stayed airborne for seven hours, that would suggest that it flew until it ran out of fuel, or close to the limit of its range. That’s about how long a plane with fuel for a six-hour flight to Beijing can fly.

No longer is the search focused on the waters between Malaysia and Vietnam. A multinational fleet of ships and planes is scouring vast stretches of the Indian Ocean and much of mainland Asia. In a typical aviation disaster the search narrows with time, but this one has expanded to cover immense areas of the world’s third-largest ocean and its largest continent.

By the prime minister’s count, 14 countries, 43 ships and 58 aircraft are looking for the plane. Many of the countries that have joined forces have been at each others’ throats in recent years in territorial disputes over the South China Sea.

The investigation of Flight MH370 has drawn an improvised team of aviation agencies from Malaysia, China, the United States and Britain. American officials from the FBI, the Federal Aviation Administration and the National Transportation Safety Board have converged on Kuala Lumpur.

So far no one has a solid “theory of the case,” as lawyers say. Mechanical malfunction — say, a sudden decompression that renders everyone onboard unconscious but lets the plane continue to fly — is still possible. A fire, perhaps from lithium batteries in the cargo hold, is another possibility.

But investigators suspect the disappearance could have been the result of a criminal act by a cockpit intruder or by someone in the crew. If that’s the case, there’s no obvious motive, no obvious perpetrator, no organization taking responsibility, no clear red flag about anyone onboard and nothing but speculation on how the hijacking or sabotage might have been carried out. The most essential question — where is the plane? — is unanswered.

U.S. intelligence and counterterrorism officials are reluctant to jump to conclusions about what happened to the plane because there’s no crime scene and no evidence it was an act of terrorism.

“We haven’t found the plane yet,” one official said.

Asked whether the aircraft could have been hijacked, another official answered: “Where are the demands?”

With a near-vacuum of solid information about the plane’s fate, speculation has flourished, and increasingly elaborate and exotic scenarios are floating about on TV and the Internet. Grieving relatives of the passengers, many of them staying in a hotel in Beijing and growing increasingly angry and dismayed by the lack of information, are left to hope that one of these improbable scenarios is true — that this is a stolen plane, and that somehow there was no crash but instead a landing on a secret runway, perhaps some abandoned jungle airstrip from World War II.

That stretches credulity for most aviation experts. The potential route into mainland Asia goes through contested territory bristling with radar. This leads investigators to think a flight path into the remote Indian Ocean, away from radar installations, is more plausible.

The Malaysian prime minister said the plane’s last communication with the satellite “was in one of two possible corridors: a northern corridor stretching approximately from the border of Kazakhstan and Turkmenistan to northern Thailand, or a southern corridor stretching approximately from Indonesia to the southern Indian Ocean.”

A U.S. official with knowledge of the investigation, speaking on background with aviation reporters, explained late Friday that the satellite information comes from Inmarsat, a company that has put a geostationary satellite 22,300 miles above the Indian Ocean. The plane and the satellite were not exchanging any data during what the U.S. official described as a “four- or five-hour” period.

The system onboard the plane that can communicate with the satellite is called ACARS, for Aircraft Communications Addressing and Reporting System. For some reason it was turned off or became disabled early in the flight, before the shutdown of the plane’s transponder signal.

But as with many such electronic devices, the ACARS system is never completely off. There is still an hourly “handshake” with the satellite.

This hourly electronic embrace provided the clue that the plane was still flying. But where? The satellite doesn’t pick up the plane’s location. Instead, the satellite can discern the extent to which its antenna would need to be adjusted to pick up the strongest possible signal from the plane, the U.S. official said. The satellite doesn’t know where to point, just how far off from perfect its current antenna alignment is.

This brings into play elementary school geometry: The plane, after many hours of flying, must be somewhere along the arc of a circle that has a diameter of thousands of miles.

That leads to the prime minister’s explanation that the plane’s final handshake with the satellite occurred when the plane was somewhere out there in a “corridor,” either one stretching from Thailand to Central Asia or one sweeping down through the Indian Ocean.

“We’ve never had to use satellite handshaking as the best possible source of information,” the U.S. official said. “Thirty-six hours ago we had not even heard of a satellite handshake.”

Like ‘mowing your lawn’

Military searchers face a daunting task of trying to find evidence of an airplane that could be at the bottom of the sea anywhere in thousands of square miles of open water.

“This is unprecedented,” said Cmdr. William Marks, spokesman for the U.S. Navy’s forward-deployed 7th Fleet, which is leading the operation to the west of Malaysia. He is stationed on the USS Kidd, a destroyer in the Indian Ocean.

The United States also has two helicopters and two surveillance planes — the P-3C Orion and the P-8 Poseidon — helping to look for the airliner. In a typical day, surveillance planes go on nine-hour missions. The helicopters fly for about three hours, return, refuel and go out again.

Marks compared the search process to “mowing your lawn,” where you move methodically in a pattern.

“You can go in an up-and-down pattern. Or you can start in a point and do an expanding square. And loop around, getting bigger and bigger.” The latter method, he said, is used when there’s a likely search position. In this case, with so much ocean to cover and few clues, they’ve been going up and down.

Back on land, Malaysian officials hold daily news briefings at the Sama-Sama Hotel, which is connected by a walkway to the main international airport terminal outside Kuala Lumpur. The deluxe hotel has an aviation theme; the briefings take place in a basement-level auditorium across from conference rooms named “Airbus,” “Boeing 1,” and “Boeing 2.”

In every seat and pressed against the walls are 300 or 400 journalists. Two or three dozen cameras are set up in the back. The news conferences have the feel of an unruly classroom. An emcee arrives well ahead of the “guests” and lays down the ground rules: Domestic media ask questions first. No shouting. Silence is mandatory during answers.

The briefings are conducted by the defense minister, Hishammuddin Hussein, and the civil aviation director, Azharuddin ­Abdul Rahman. Their answers have gotten more obfuscatory as the days have passed.

Before the prime minister spoke Saturday, the emcee announced that there would be a statement only — no questions allowed until a separate briefing by other officials at 5:30.

But the 5:30 news conference was cancelled soon thereafter on grounds that the prime minister had said all that needed to be said.

“Go watch a movie,” the emcee told reporters.

A simple hypothesis

The initial assumption about the missing plane was simple and sad: The plane had gone down somewhere in the water where the Gulf of Thailand meets the South China Sea. Presumably, its wreckage would float to the surface along with an oil slick that would be hard for search planes to miss.

When the first day’s search came up empty, experts recalled that the hunt for an Air France plane that crashed in the Atlantic in 2009 went on for several days before the first wreckage was found.

But now multiple anomalies point to the possibility of a criminal act.

First, the ACARS stopped transmitting as if someone had turned it off. Then, but not simultaneously, the transponder on the plane went silent. In a catastrophic malfunction, such as an explosion, these devices would more likely cease transmitting at the same time.

Had there been a hijacking underway, the pilot could have turned the call sign of the transponder to 7500, a universal code for hijacking. That didn’t happen.

Mikael Robertsson, co-founder of Flightradar24, a company that had a radar receiver on the Malaysian coast that tracked Flight MH370 as it flew toward Vietnam, said the disappearance of the plane during the handoff period between Malaysian and Vietnamese air traffic control could be significant.

“If you are planning to do something strange or bad, this is a good time to do it,” Robertsson said. “No one is really following your flight between the handover.”

Military radar showed that the plane turned west and flew back across the Malay Peninsula. A U.S. official said the radar showed that the plane climbed to 45,000 feet at one point and, as the official put it, “jumped around a lot.”

Most theories about the case carry a logical flaw. For example, experts have discussed the possibility that a crew member with a death wish might have intentionally crashed the plane. But that would have required wresting control of the cockpit from other crew members, and it would not explain why the plane apparently flew for many more hours.

A bomb explosion seemed plausible, but that would have showered debris and oil from 35,000 feet across such a wide expanse of ocean that it would be hard to miss.

A senior U.S. official said authorities have gone over fingerprint records and found nothing suspicious about two passengers with stolen passports nor any sign of terrorist involvement.

“The two things missing here are the plane and patience,” said Oliver McGee, a former senior Transportation Department official and a professor of mechanical engineering at Howard University. “People always want to find the solution to the mystery. It’s a natural urge.”

Besides all the talk of satellites, pings, transponders, circuit breakers, and so forth, what investigators also have on their side are basic scientific principles, he said. Like everything else in this world, planes are bound by fundamental rules of science — things like fuel burn, lift, weight ratios and, not the least, gravity.

“Planes don’t just vanish and don’t just fall out of the sky. They go up and they come down,” he said.

“It’s just a matter of time,” McGee said. “People should be thinking more in terms of weeks and months.”

Harlan reported from Kuala Lumpur. Annie Gowen in New Delhi; William Wan and Simon Denyer in Beijing; and Alice Crites, Adam Goldman, Sari Horwitz and Ernesto Londoño contributed to this report.

Chico Harlan covers personal economics as part of The Post's financial team.

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